1. Field of the Invention
The present invention relates to the devices and methods for controlling the excretion of waste from the human body, and more particularly, to an artificial rectum and method for selectively controlling defecation in colostomy patients due to colorectal cancer, disease, injury, birth defect, or other causes.
2. Background of the Related Art
The rectum with sphincter musculature provides the collection point and discharge mechanism for waste elimination. Cancers of the colon and rectum are two of the most common cancers in the United States. Together, they are referred to as colorectal cancer.
Surgical removal of a malignant tumor is the most common treatment for colorectal cancer. The diseased portion of the colon and/or rectum is removed, and in most cases, the healthy portions are reattached. However, approximately 5% of patients with colorectal cancer require a colostomy because of the extent of the disease or its location. In such cases, a surgical opening is made through the abdomen to provide a new path for waste elimination, whereby the patient is required to excrete through a stoma (small aperture in the skin) and into a colostomy bag. Since the colostomy bag can only be used for liquid feces, the surgeon also removes the large intestine, even though a majority of it might be healthy, in order to prevent the formation of any solid feces and thereby ensure the proper passage of the feces through the stoma and into the colostomy bag.
A colostomy also may be performed to treat traumatic injuries to the bowel, diverticulitis, and inflammatory bowel disease, when other treatment measures fail. Currently, there is a population of about 850,000 people in North America that live with the condition, with about 7,000 new cases of colostomy due to colorectal cancer reported annually based on Cleveland Clinic statistics. Worldwide, U.N. statistics estimate 3.5 million patients in developed countries alone live with colostomy.
Several devices have been developed to allow such patients limited control over their need to eliminate wastes from their bodies. For example, U.S. Patent application Ser. No. 2001/00223337 A1 to Lapcevic shows an apparatus that evacuates human waste products from a stoma which includes a battery-powered or manual evacuator pump activated by an external switch or operator to empty the shortened bowel. The evacuator assembly is adapted to seal over the stoma during operation, after which it may be removed.
Further examples include U.S. Pat. No. 4,351,322 to Prager which shows a stoma control device having a ring for surgical implantation around an emerging bowel. A plug is adapted to fit within the distal end of the bowel which selectively inflates to engage the surrounding tissue and ring to block the stoma.
Still further, U.S. Pat. No. 4,217,899 to Freir shows a prosthesis permanently attached to the distal end of the intestinal tract that allows waste products to accumulate. Elimination of the waste products is through a removable assembly of an elastic liner and support structure that communicates with the affixed portion of the prosthesis to collect the waste.
In light of the foregoing, a need exists for an artificial rectum which provides selective control over the excretion of fecal matter to obviate the need for removal of the large intestine in a patient and the associated use of a stoma for collection/removal of waste products.
The present invention is directed to an artificial rectum and method for selectively moving feces through the lower gastro-intestinal tract and out of the body. Accordingly, a principal advantage of the present invention is the elimination of the need for a colostomy bag and stoma in patients who undergo a colostomy. An inlet to the artificial rectum is operatively connected to the distal end of the large intestine, and communicates fecal waste to a one-way liquid-tight inlet valve and pump, such as a macerator-type pump, mounted within an inner body substantially inserted into and retained by an outer body of the artificial rectum. The inlet valve and pump work in tandem to control the flow of fecal matter through the artificial rectum and out of the body. Such a configuration has the added advantage of permitting removal of the inner body from the permanently installed outer body of the artificial rectum for subsequent medical examination of the large intestine (e.g. coloscopy) or replacement of the inner body and moveable parts mounted thereto. An outlet or tissue ingrowth flange is formed on the external end of the outer body and can be surgically connected to the patient""s skin surrounding the remaining portion of the sphincter muscle. In use, the patient actuates a remote control unit, for example, to open the inlet valve and drive an impeller of the pump to discharge feces therethrough. The patient ceases defecation by stopping the impeller and shutting the inlet valve.
In a currently preferred embodiment of the present invention, the artificial rectum includes means for permitting the patient to selectively control the operation of the artificial rectum. In one such embodiment, control is achieved through the use of a remote control unit functionally coupled, such as by RF, to the pump and/or inlet valve.
Another embodiment of the present invention includes a one-way liquid-tight valve extending through a side-wall of the artificial rectum and connected in fluid communication to an outlet conduit to allow the release of gaseous waste.
The present invention also is directed to a method for providing selective control of defecation by a colostomy patient. The method comprises the following steps:
providing an artificial rectum having an inlet, an outlet, and a flow control device coupled in fluid communication between the inlet and the outlet;
connecting the inlet or tissue ingrowth collar of the artificial rectum in fluid communication with a large intestine of the patient;
connecting the outlet or tissue ingrowth flange of the artificial rectum to the anus and/or tissue adjacent to the anus of the patient; and
receiving fecal matter from the large intestine through the inlet of the artificial rectum, and controlling the flow control device to selectively move the fecal matter between the inlet and the outlet, and, in turn, discharge the fecal matter through the outlet to thereby control defecation of the patient.